The present invention relates generally to a screening apparatus for separating particulate materials, such as aggregate, and, more particularly, to a chute assembly for directing the discharge of the screening apparatus to desired locations.
A vibratory screen apparatus is utilized in many industries to separate particulate material into classifications according to size parameters. Conventional screening devices include a plurality of vertically spaced screen members that are in decreasing sizes so that material particles having size dimensions that will not permit the passage of the particles through the openings in the wire mesh screen are discharged off the end of the screen to be collected by associated collection devices and segregated appropriately. An example of a vibratory screen apparatus can be found in U.S. Pat. No. 5,816,413, issued to Joseph Boccabella on Oct. 6, 1998. In this Boccabella patent, the screen decking is formed as modular components that are mounted on a frame support by magnetic holding devices positioned by locator pins.
Delivery chutes are associated with the vibratory screen apparatus to receive the separated particle material from the individual screens and direct the flow of separated particulates to a desired location. An example of a delivery chute can be found in U.S. Pat. No. 6,279,715, granted on Aug. 28, 2001, to Harold Herren in which a top chute or deck delivers the particulate material discharged off the top screen to a conveyor for subsequent handling at a remote location, while a second chute or deck directs the discharge of particulate material off of a second screen member into a pile next to the vibratory screen. Presumably, the material passing through the second screen member is collected beneath the vibratory screen apparatus. In the Herron patent, the chutes are formed with a removable liner that is retained by a framework welded to the floor of the chute. The removable liner is formed in different sized modules that are preferably cut to size and numbered to prevent confusion in the installation of the panels.
Removable liners for chutes can also be found in U.S. Pat. No. 4,381,834, granted to John Leinenger on May 3, 1983, in which the elongated liner members are engaged with grooves formed into the floor of the chute to permit removal thereof. In U.S. Pat. No. 6,216,842, issued to Scott Beale on Apr. 17, 2001, in which a low friction liner is placed in a delivery chute to span across the floor of the chute. A modular wear pad for a delivery chute is taught in U.S. Pat. No. 5,735,377, granted on Apr. 7, 1998, to Harold Herren in which a threaded bolt is attached to a rubberized panel for allowing the panels to be mounted on a sub-structure by nuts detachably connected to the threaded bolt.
The formation of wear panels by attaching a wear resistant layer to a lower support substrate is taught in U.S. Pat. No. 4,529,660, issued on Jul. 16, 1985, to Robert Heim, although the disclosed liner is not in a modular format. The Heim liner utilizes a magnetic substrate to facilitate replacement of the liner when the material has been worn substantially, thus there is no mechanical connection between the liner and the frame supporting the liner defining the floor of the chute. U.S. Pat. No. 3,524,666, granted on Aug. 18, 1970, to Harold Schilf, discloses a floor clip that can be attached to a wooden deck member for engagement with an angle iron frame member beneath the flooring and providing support therefor.
Conventional roll away chutes have multiple decks to receive the discharge from corresponding screen members on vibratory screening apparatus. Such devices are formed with gates built into the floor of selected chutes to permit material flowing along one chute to be mixed or blended with the material corresponding to the chute immediately below the one chute. Conventional blending gates are hard to operate and are heavy and cumbersome to manipulate. Furthermore, the floor surface of the chutes and the blending gates forming a part of the floor surface are subject to heavy wear. For applications such as the separation of aggregates, or other hard particles, the wear liner must be replaced frequently. For conventional chute systems, replacement of the liner means that the entire liner defining the floor of the chute needs to be cut away from the support structure and a new liner welded into place. Such maintenance activity is extremely difficult and is complicated by the narrow passageways defined by the respective chutes. Other commercially available liner devices, such as the Herren liners disclosed in U.S. Pat. No. 5,735,377, still require access by the people replacing the liners to apply tools to the fasteners to effect removal of the liners.
Some modular liner devices, such as the Herren structure disclosed in U.S. Pat. No. 6,279,715, have very little commonality in the different panels installed on the floor of the chute. As a result, the wear surface panels are not interchangeable and require specific replacements to be stocked in order to quickly maintain and service the chute apparatus. Since the wear surface can be formed of different materials, such as rubber, urethane, chromium carbide and ceramics, each of which establish different performance characteristics, the decision to try a different wear surface on conventional chute designs requires a major investment in time and money.
It would be desirable to provide a wear surface system that would be more conducive to changing wear surface materials. It would also be desirable to provide a modular wear panel system that requires a minimum of replacement parts to be kept in stock, and would require little or no tools to effect a change in the panels. Such modular panels would preferably only require a minimal amount of time to replace a panel, or even the entire surface of a chute. Lastly, it would be desirable to provide a modular wear surface panel configuration that would be easy to convert blending gates from one selected position to another.